Rattlesnakes
Integrated Pest Management In and Around the Home
The rattlesnake is California’s only
native venomous snake. Nine species
are found in various areas of the state
from below sea level to about 11,000
feet. Their size may vary, and adults of
some species may reach 6 feet in length.
Rattlesnakes are an important part
of the ecosystem, feeding on rodents,
birds, and other small animals.
Rattlesnakes have a distinctive, triangular-shaped head, which can be
helpful in their identification (Figure 1);
and as their name implies, most have
a rattle on the tail end. The harmless
gopher snake (Pituophis catenifer) appears similar to rattlesnakes and can
alter its posture to mimic the triangular
head shape (Figure 2) but will always
lack a rattle. The rattle lies at the end of
the tail and is composed of interlocking
horny segments of shed skin (Figure
3). Young rattlesnakes are born with a
small rattle or button (Figure 4). A new
segment is formed each time the skin
is shed, which may occur several times
a year. The size of the rattle is only a
rough indicator of age because the terminal segments often break off on older
snakes. Because rattles can shorten or
be broken off completely, the lack of a
rattle does not mean the snake is not a
rattlesnake.
The most widespread rattlesnake in
California is the western rattlesnake
(Crotalus oreganus), found from the
northern part of the state as far south
as Santa Barbara County and from sea
level to 7,000 feet. Two closely related
species (C. helleri and C. lutosus) are
found in coastal Southern California
and in the northern Sierra Nevada,
respectively. The sidewinder (C. cerastes) is the smallest rattlesnake and is so
named because of its peculiar method
of sideways locomotion. The sidewinder is sometimes called the horned
Figure 1. A western rattlesnake
(Crotalus oreganus) has a triangular
head, elliptical pupils in the eyes, and
is often heavy-bodied with a rattle at
the end of its tail. Its head is usually
noticeably larger than its neck.
Figure 2. A harmless gopher snake
(Pituophis catenifer) will sometimes
mimic a rattlesnake by vibrating its
pointed tail and shaping its head into a
triangle. However, gopher snakes never
have a rattle on their tails, are usually
thinner throughout the body, have a
glossy body, have round pupils in their
eyes, and their heads are only slightly
larger than their necks.
Figure 3. A closeup photo of the tail
of a Mojave rattlesnake (Crotalus
scutulatus) showing the interlocking segments of the rattle that are
added each time the animal sheds as
it grows.
Figure 4. Like all rattlesnakes, this
young speckled rattlesnake (Crotalus
mitchellii) is born with only a button
on its tail in place of its rattle. Its rattle
will grow in length each time the animal sheds as it grows.
rattler because of the hornlike scales
above its eyes. It is most commonly
found in sandy desert areas from below sea level to 6,000 feet. The Mohave
rattlesnake (C. scutulatus) ranges across
the desert and foothills of southeastern California from sea level to higher
elevations. The southwestern speckled
rattlesnake (C. mitchellii) ranges from
Baja California northward across much
of the Colorado, Mojave, and Sonoran
Deserts, overlapping with the red dia-
mond rattlesnake (C. ruber) in western
parts of its range and the sidewinder
farther east. The Panamint rattlesnake
(C. stephensi) is closely related but has
a more northerly distribution in the
inland desert regions of Southern California. The red diamond rattlesnake
is found in Baja California and in
southwestern California south of Los
Angeles. The western diamond-backed
rattlesnake (C. atrox) is seldom seen in
California but occurs in the extreme
PEST NOTES
Statewide Integrated Pest Management Program
Publication 74119
December 2014
December 2014
Rattlesnakes
southeastern part of the state in desert
regions.
elliptical eye pupil
nostril
BIOLOGY AND BEHAVIOR
loreal pit
Most rattlesnakes forage for prey in or
near brushy or tall grass areas, rock
outcrops, rodent burrows, around and
under surface objects, and sometimes
in the open. Adults eat live prey, primarily rodents; the young consume
mostly lizards and young rodents. To
catch their prey, rattlesnakes wait until a prey animal is nearby. The snake
strikes with two large fangs that inject
venom (Figure 5). This subdues and
usually kills the prey, which is then
swallowed whole. Rattlesnakes feed on
carrion less frequently.
When inactive, most rattlesnakes
seek cover in crevices of rocks, under
surface objects, beneath dense vegetation, and in rodent burrows. In
some areas, rattlesnakes hibernate for
several months in the crevices of rock
accumulations. Unlike many reptiles,
rattlesnakes give birth to live young.
Pit viper head showing the elliptical pupil
and location of the loreal pit.
duct
venom gland
fangs
Rattlesnake venom injection system.
Rattlesnake head. Note the triangular shape.
Figure 5. Distinguishing features of pit
viper.
Rattlesnakes are among the group of
snakes called pit vipers because of
the small pits on each side of the head
between the eye and nostril (Figure 5).
These pits are temperature-sensitive
structures that assist the snake in
finding prey, even in complete darkness. The tongue is also used to detect
the scent of prey. Rattlesnakes have
a specialized venom delivery system.
Venom is produced in glands behind
the eyes and then flows through ducts
to the hollow fangs. Normally the fangs
fold back against the roof of the mouth
and when a snake strikes, the fangs
pivot forward to inject venom (Figure
5). Rattlesnakes may occasionally bite
without injecting venom, often called a
‘dry’ bite. However, even after its death,
a rattlesnake can still inject venom for
an hour or more by reflex action. Caution, therefore, is advised when handling what appears to be a dead snake.
Snake Bites
What Should I Do for Initial First Aid?
Because most Californians live in rattlesnake country, a snakebite emergency plan
should be developed before it is needed. If you are less than one hour from the nearest
emergency room, initial treatment is relatively simple:
• Try to calm the victim.
• Gently wash the area with soap and water.
• Apply a cold, wet cloth over the bite.
• Transport victim to the nearest emergency facility for further treatment.
• Phone ahead to notify the emergency facility that a snakebite victim is being brought in.
• If safe to do so, have someone photograph the snake so that identification
can be made to aid in treatment.
What should NOT be done after a rattlesnake bite?
Several DON’Ts are very important to remember:
•
•
•
•
•
•
•
Newborn snakes require protection for
1-2 weeks and are likely to be born in
abandoned rodent burrows, rock crevices, or in other secluded places.
DON’T apply a tourniquet.
DON’T pack the bite area in ice.
DON’T cut the wound with a knife or razor.
DON’T use your mouth to suck out the venom.
DON’T let the victim drink alcohol.
DON’T apply electric shock.
DON’T use a snakebite kit as these do not work and can cause more damage.
Call: 1-800-222-1222 any time, any place in California (California Poison Control
System)
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In the United States, about 1,000 rattlesnake bites are reported annually, although typically fewer than 4 people
die from these bites in a given year.
Although seldom fatal, bites can be extremely painful and can lead to severe
tissue loss and medical trauma. It is
important to never handle rattlesnakes,
not even dead ones.
Those who enjoy hiking should determine first whether rattlesnakes are
found in that area and under what
conditions they might be encountered;
however, rattlesnakes may be very
sparse or nonexistent across parts of
their range. In addition, they can sometimes be transported into areas outside
their normal range, either by humans
or by natural mechanisms such as
floods. If rattlesnakes are in the area,
they will most likely be hidden in rock
crevices, under logs, in heavy brush, or
in other areas where they are protected,
including tall grass; but they can also
be found on roads, paths, and other
areas where cover is limited. Be careful when moving brush, wood, logs, or
December 2014
other debris. In rattlesnake country, be
alert when kneeling down to work in
the garden and watch where you step.
Since rattlesnakes are often well camouflaged and wait quietly for prey, they
can be difficult to see. In the wild, rattlesnakes should be left alone as they
present little potential hazard. In fact,
more than half of venomous snakebites
in the United States occur as a result
of a person bothering, handling, or
harassing a snake, and approximately
half of snakebite patients report ingesting alcohol prior to being bitten. Thus,
it would seem that one of the key ways
to avoid being bitten is to avoid harassing venomous snakes, especially if
you are under the influence of alcohol.
However, rattlesnakes can still present
some risk even if they are not being
pestered. For many people, having
them around the home or garden is not
acceptable. Fortunately, there are ways
to minimize potential hazards.
Rattlesnakes
LEGAL STATUS
The nine species of rattlesnakes found
in California are not considered endangered or threatened. California
Department of Fish and Wildlife Code
classifies rattlesnakes as native reptiles.
California residents can take most
rattlesnake species on private lands in
any legal manner without a license or
permit, although a bag limit of two still
applies. Additionally, the red diamond
rattlesnake (C. ruber) is prohibited from
being taken or killed by state wildlife
regulation.
MANAGEMENT
Rattlesnakes add to the diversity of our
wildlife and are important members
of our ecosystem. They can reduce the
number of disease carrying rodents
and other pest species. In general, they
should be left alone, whenever possible,
especially in wildland areas. Nonven-
What Can be Done to Prevent a Bite?
Hands, feet, and ankles are the most common sites for rattlesnake bites. Using some
common sense rules can prevent most snake bites.
• Never go barefoot or wear sandals when walking in areas where you cannot
clearly see where you are placing your feet. Always wear hiking boots.
• Always stay on paths. Avoid tall grass, weeds, and heavy undebrush where snakes
may be present.
• Always look for concealed snakes before picking up rocks, sticks, or firewood.
• Always check carefully around stumps or logs before sitting.
• When climbing, always look before putting your hands in a new location. Snakes
can climb walls, trees, and rocks and are frequently found at high altitudes.
• Never grab what appear to be sticks or branches while swimming; rattlesnakes
are excellent swimmers.
• Baby rattlesnakes are venomous! They can and do bite. Leave them alone.
• Never hike alone. Always have a buddy to help in case of an emergency. Learn
basic lifesaving skills.
• Never handle freshly killed snakes. You may still be bitten.
• Never tease a snake to see how far it can strike. You can be several feet from the
snake and still be within striking distance.
• Don’t keep rattlesnakes as pets. Many rattlesnake bites occur when people tease or
play with their “pet” rattlesnake.
• Teach children to respect snakes and to leave them alone. Curious children who
pick up snakes are frequently bitten.
• Always give snakes the right of way!
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omous snakes should also be left alone
wherever found.
Because of the danger rattlesnakes
pose to people, pets, and domestic
animals, it can be necessary to exclude
or remove them from around homes
and gardens.
DETECTION
It is difficult to detect rattlesnakes
because they are not easy to see or to
find in their hiding places. Be alert to
the potential for their presence during
the times of year when rattlesnakes
are generally active in your region. If
rattlesnakes become exceptionally numerous in an area, sightings by neighbors may alert you to expect a problem.
Snake populations may fluctuate from
year to year; this is thought to be related in part to the availability of prey.
Some animals, such as peacocks, turkeys, and dogs, can be good sentinels
for detecting rattlesnakes. If your dog
behaves in an unusual manner, such
as excessively barking or whining, it
would be wise to investigate for the
presence of a snake. A veterinarian
should immediately attend to dogs or
domestic animals bitten by a rattlesnake. If you have a snake-proof fence,
be sure to check its integrity prior to
the time when snakes become active in
the late winter or early spring. Remember that keeping the rodent population
in and around your yard under control is an excellent way to discourage
snakes of all kinds.
Habitat Modification
One of the best ways to discourage
rattlesnakes from inhabiting gardens
and homes is to remove suitable hiding
places. Heavy brush, tall grass, rocks,
logs, rotten stumps, lumber piles, and
other places of cover should be cleaned
up. Keep weeds mowed close to the
ground or remove them completely.
Since snakes are often attracted to
areas in search of prey, eliminating
rodent populations, especially ground
squirrels, meadow voles, deer mice,
rats, and house mice, is an important
step in making an area less attractive
for snakes. Rattlesnakes cannot dig
burrows but will use those dug by
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rodents. After controlling rodents, fill
in all burrows with soil or sod and pack
down firmly.
Exclusion
Rattlesnakes may seek refuge beneath
buildings. If there is a gap or opening,
they will enter and inhabit a building, just as house mice do. Sealing all
cracks and other openings greater than
1/4inch can prevent them from entering.
Gaps beneath garage doors are often
large enough to permit snakes to enter,
especially young ones. In summer, rattlesnakes may be attracted to cool and/
or damp places, such as beneath buildings and in basements. Access doors on
crawl spaces should be inspected carefully for breaks or gaps. Use caution if
you must crawl under a house or other
building. Hot tub or swimming pool
pump enclosures may provide cover if
they are not well sealed. The dampness
associated with ornamental water fountains, pools, and fishponds may also
make the surrounding area attractive
to snakes.
Fences
Snakes can be excluded from an area
by installing a snake-proof fence. While
expensive, fences are often necessary for children’s play areas. Be sure
to make gates tight fitting and keep
vegetation and debris from collecting
around the fence. Snakes can climb accumulated vegetation and gain access
to the top of the fence. Check the fence
frequently to be sure it has not been
damaged in any way.
Repellents
Over the years various home remedies
have been suggested to repel snakes,
such as placing a horsehair rope
around your sleeping bag, sprinkling
sulfur dust, or scattering mothballs
around the area to be protected. Unfortunately, none of these remedies work.
Despite what you may hear, there are
no plants that repel snakes. Currently,
several commercially available chemical snake repellents are on the market,
but none of them have been proven to
work well enough to warrant recommendation.
Rattlesnakes
Biological Control
Several predators feed on rattlesnakes,
including the kingsnake, which swallows them whole. Unfortunately, the
number of rattlesnakes eaten by predators is insignificant in reducing the
problem you might encounter around
your home or garden. For this reason,
relocating kingsnakes to your property
is not recommended.
Other Control Methods
Remember, if left alone, a snake is likely
to move on to another area. Also recall
that most rattlesnake bites occur when
inexperienced people try to pick up,
pester, move, or kill a rattlesnake. If
you would prefer the snake be removed,
it is best to call a professional pest or
wildlife control operator who specializes in snake removal. Your local county agricultural commissioner or UC
Cooperative Extension office may be
able to direct you to professionals who
remove rattlesnakes. A final course of
action may be to kill the rattlesnake.
However, this option is not generally
recommended since rattlesnakes only
bite in self defense and attempting to
kill them can, and sometimes does,
result in a person getting bitten. Even a .
dead rattlesnake can have a bite reflex
and is capable of delivering venom.
Rattlesnakes are natural and important
predators and automatic killing of them
is not recommended any more than is
the automatic killing of coyotes, mountain lions, or bears, all of which can
very rarely harm people.
REFERENCES
Walter, F. G., U. Stolz, F. Shirazi, J. McNally. 2009. Epidemiology of severe and
fatal rattlesnake bites. Philadelphia:
American Association of Poison Control
Centers’ Annual Reports. Clin. Toxicol.
47:663-669.
Salmon, T. P., D. A. Whisson, and R. E.
Marsh. 2006. Wildlife Pest Control Around
Gardens and Homes. 2nd ed. Oakland:
Univ. Calif. Agric. Nat. Res. Publ. 21385.
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December 2014
Rattlesnakes
AUTHORS: Brian Todd, Dept. of Wildlife,
Fish and Conservation Biology, UC Davis.
Revised based on a previous version
authored by T.P. Salmon, D.A. Whisson and
R.E. Marsh.
ILLUSTRATIONS: Fig. 1. A. G. Clause,
Univ. of Georgia; Fig. 2. T. Young; Fig. 3.
J. M. Peaden, U.C. Davis; Fig. 4. William
Flaxington ©2009; Fig. 5. Reproduced from
Wildlife Pest Control Around Gardens and
Homes. 2nd ed. UC ANR Publ. 21385.
TECHNICAL EDITOR: K. Windbiel-Rojas
EDITOR: K. Beverlin
This and other Pest Notes are available at
www.ipm.ucanr.edu.
University of California scientists and other
qualified professionals have anonymously peer
reviewed this publication for technical accuracy.
The ANR Associate Editor for Pest Management
managed this process.
To simplify information, trade names of products
have been used. No endorsement of named products
is intended, nor is criticism implied of similar products
that are not mentioned.
This material is partially based upon work
supported by the Extension Service, U.S. Department
of Agriculture, under special project Section 3(d),
Integrated Pest Management.
Produced by:
Statewide Integrated Pest Management Program
University of California
2801 Second St.
Davis, CA 95618-7774
For more information, contact the University of
California Cooperative Extension office in your
county. See your telephone directory for addresses
and phone numbers, or visit http://ucanr.edu/
County_Offices/.
WARNING ON THE USE OF CHEMICALS
Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations
given on the container label. Store all chemicals in the original, labeled containers in a locked cabinet or shed,
away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock.
Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans.
Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens
containing fruits or vegetables ready to be picked.
Do not place containers containing pesticide in the trash or pour pesticides down the sink or toilet. Either use
the pesticide according to the label, or take unwanted pesticides to a Household Hazardous Waste Collection
site. Contact your county agricultural commissioner for additional information on safe container disposal and
for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers
by following label directions. Never reuse or burn the containers or dispose of them in such a manner that
they may contaminate water supplies or natural waterways.
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It is the policy of the University of California (UC) and the UC Division of Agriculture & Natural
Resources not to engage in discrimination against or harassment of any person in any of its programs
or activities (Complete nondiscrimination policy statement can be found at http://ucanr.edu/sites/anrstaff/
files/183099.pdf).
Inquiries regarding ANR’s nondiscrimination policies may be directed to Linda Marie Manton,
Affirmative Action Contact, University of California, Agriculture and Natural Resources,
2801 Second Street, Davis, CA 95618, (530) 750-1318.
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